Predominant Culturable Bacillus Species in Japanese Arable Soils and Their Potential as Biocontrol Agents
Predominant Culturable Bacillus Species in Japanese Arable Soils and Their Potential as Biocontrol Agents
复制标题
DOI：
10.1264/jsme2.20.61
复制
发表时间：
2005-03
影响因子：
2.2
通讯作者：
T. Nishijima;K. Toyota;M. Mochizuki
中科院分区：
文献类型：
--
作者：
T. Nishijima;K. Toyota;M. Mochizuki
为了揭示日本耕地土壤中主要的可培养芽孢杆菌物种，从日本不同的土壤中分离出好氧孢子形成细菌，并根据16 S rDNA序列估计其产芽孢位置。还从在土壤中生长4周的番茄根中分离芽孢杆菌属物种，以估计土壤和根分离物之间的产芽孢位置的差异。土壤和番茄根中可培养芽孢杆菌的数量分别为6.4 ~ 7.4 log cfu g-1土壤和4.7 ~ 6.7 log cfu g-1根，土壤和根中芽孢杆菌占可培养细菌总数的比例分别为3.8%~ 17.9%和0.1%~ 6.7%。土壤和根系中可培养芽孢杆菌的数量和百分比差异极显著（P=0.0000和0.0023），表明土壤中芽孢杆菌的数量比根系中芽孢杆菌的数量多。共108个菌株的特点是使用限制性片段长度多态性（RFLP）的方法和部分16 S rDNA序列。它们分属于芽孢杆菌属、短芽孢杆菌属和类芽孢杆菌属等22个种。未分离出固氮剂。优势种为巨大芽孢杆菌，42株（39%）。一些物种，如芽孢杆菌luciferensis和短芽孢杆菌agri，只分离自番茄根，被认为是更适应根际比土壤。在108个分离物中，只有一株巨大芽孢杆菌N2 S6对青枯雷尔氏菌引起的番茄青枯病表现出一致的拮抗活性。
To reveal predominant culturable Bacillus species in Japanese arable soils, aerobic spore-forming bacteria were isolated from different soils in Japan and their phylogenic positions were estimated from the 16S rDNA sequences. Bacillus species were also isolated from tomato roots grown in soils for 4 weeks to estimate the difference in phylogenic positions between soil and root isolates. The number of culturable Bacillus species ranged from 6.4 to 7.4 log cfu g-1 soil and 4.7 to 6.7 log cfu g-1 root in soils and tomato roots, respectively, and the proportion of Bacillus species among total culturable bacteria ranged from 3.8% to 17.9% and 0.1% to 6.7% in soils and roots, respectively. The differences in the number and percentage of culturable Bacillus species between the soils and roots were highly significant (P=0.0000 and 0.0023, respectively), indicating that Bacillus species were more predominant in soil than in root. A total of 108 isolates were characterized using the restriction fragment length polymorphism (RFLP) method and partial 16S rDNA sequences. They affiliated to 22 species including the genus Bacillus, Brevibacillus and Paenibacillus. No nitrogen fixers were isolated. The predominant species was Bacillus megaterium to which 42 isolates (39%) belonged. Some of the species, such as Bacillus luciferensis and Brevibacillus agri, were isolated only from the tomato roots and considered to be more adapted to the rhizosphere than soil. Among 108 isolates, only one strain, N2S6, belonging to Bacillus megaterium, showed consistent antagonistic activity against the bacterial wilt of tomato caused by Ralstonia solanacearum.